Parched Cape Town’s lesson for cities: Protect nature

After experiencing two of the driest seasons on record in 2015 and 2017, the city announced July 9 as “Day Zero” — the day when taps would be shut off. But, because of water conservation efforts, the city has since announced that “Day Zero” would not occur this year.

Cape Town isn’t alone: Climate change is causing regions to experience droughts and floods more extreme than they’re used to, affecting everything from agriculture to access to drinking water. In honor of World Water Day on March 22, Human Nature talked to Conservation International’s freshwater lead, Robin Abell, about what cities have to do to protect their water supplies in a changing climate.

Q: What can cities due to avoid falling into the same situation as Cape Town?

A: To start: Consider nature and how it can benefit both your water quality and quantity. We all need conventional water delivery systems (such as pipes) to get water to people, but we need to complement that with nature’s delivery systems. If you get rid of your natural spaces, for example by paving over wetlands to build apartments, you may be left with water delivery systems without reliable supplies of water to deliver. Nature is a critical piece of ensuring water security.

Also, as much as possible, cities need to act proactively and think about planning for both conventional infrastructure and nature simultaneously, rather than reacting when they’re in crisis mode. That means protecting natural areas, integrating nature-based solutions (“green infrastructure”) with traditional (“gray”) infrastructure to achieve what we might call sustainable infrastructure, and encouraging citizens as well as water-using industries to use water responsibly.

A: Green infrastructure can take many forms – from big networks of protected natural areas to green roofs in cities — but all types of green infrastructure employ nature to provide ecosystem services, like reliable flows of clean water or clean air. Green infrastructure is often designed and used to provide water quality and water quantity benefits because green infrastructure reduces and treats storm water at its source, but it can also generate benefits in terms of climate change mitigation and adaptation, biodiversity conservation and human health.

Gray infrastructure typically refers to conventional, built approaches to water treatment and delivery, such as concrete tunnels and sewerage piping. Unfortunately, around the world this type of infrastructure is crumbling and is expensive to build anew. When it’s properly protected, green infrastructure can last indefinitely, whereas gray infrastructure deteriorates and needs to be maintained or replaced.

Integrated green-gray infrastructure is the idea that you plan for and invest in green and gray infrastructure simultaneously, ensuring a sustainable foundation for water security and reducing water-related risks.

GIVE BACK TO NATURE

A: Due to climate change, rainfall patterns are changing — sometimes drastically. Parts of the world are going to get drier and other parts are going to get wetter. You could even say that climate change is water change. Water will be less reliable. The patterns of water flow that we’re used to are not going to look the same in the future, so it’s going to be harder to plan for how to use our water resources. For example, rainy seasons are already shifting to much earlier or later than expected, and the lack of predictability preventing farmers to plan for growing their crops.

This is where investing in green infrastructure becomes key, because it goes hand in hand with adapting to climate change. Green infrastructure promotes resiliency for both communities and the species that rely on these systems. Healthy and resilient ecosystems are our best insurance policy against climate change’s impacts on the water cycle.

Q: What does that mean for people that are living in these areas that are going to get much drier or much wetter?

A: People are already experiencing these conditions. It’s not some vague issue we’re going to need to deal with in the future — it’s already happening, today. We know that less developed nations are often the most vulnerable to the effects of climate change because they have a lower capacity to adapt and less resources for gray infrastructure and are more reliant on climate-sensitive sectors like agriculture. Their more exposed communities will experience these harsh conditions more directly and severely, versus populations in more developed nations that have the resources to invest in gray infrastructure that can alleviate some of these impacts in the near term.

In parts of the world where there’s more direct exposure to these impacts, people have fewer options. In a lot of cases, people may need to move — driving climate-induced migration. Even cities like Cape Town have already experienced some emigration. Having to abandon your traditional homelands to go to places where there’s better water security is incredibly serious and accelerates pressure on the areas where migrants are relocating. Unfortunately, that’s not something that you’re going to have control over as an individual or as a family or as a small community. If decision-makers work together to implement natural solutions over sufficiently large areas, there can be buffering against the impacts of climate change, with more reliable water supplies.